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  • Go

Idiom #109 Number of bytes of a type

Set n to the number of bytes of a variable t (of type T).

import "reflect"
var t T
tType := reflect.TypeOf(t)
n := tType.Size()

This run-time reflection works on a value of the type T.
Note that the size does not include the memory indirectly taken by the reference fields: Strings, slices, etc.
Warning: for a given program, the size of a type is not the same on a 32-bit machine or a 64-bit machine.
N : Integer := (T'Size + 7) / 8;

T'Size returns size of T in bits. It is the minimum number of bits required to store an object of that type.
Divide by 8 to convert to bytes
New implementation...
< > ⌨
programming-idioms.org 
var t T
tType := reflect.TypeOf(t)
n := tType.Size()
N : Integer := (T'Size + 7) / 8;
n = sizeof (t);

std::size_t n = sizeof(t);
int n = sizeof(T);
int n = Marshal.SizeOf(t);
int n;
unsafe
{
    n = sizeof(T);
}
auto n = T.sizeof;
n = c_sizeof(i)
<T> int bytes(T t) {
    String s = t.getClass().getSimpleName();
    return switch (s) {
        case "Boolean" -> 1;
        case "Byte" -> Byte.BYTES;
        case "Short" -> Short.BYTES;
        case "Character" -> Character.BYTES;
        case "Integer" -> Integer.BYTES;
        case "Float" -> Float.BYTES;
        case "Long" -> Long.BYTES;
        case "Double" -> Double.BYTES;
        default -> -1;
    };
}
n := SizeOf(T);
use Devel::Size qw(total_size);
my $n = total_size $t;
n = pympler.asizeof.asizeof(t)
n = getsizeof(t)
n = ObjectSpace.memsize_of(t)
let n = std::mem::size_of::<T>();